This invention relates in general to railroad car coupling systems and, more particularly, to a system and apparatus for a knuckle coupler pin for railroad car coupling systems.
Railroad cars use couplers to attach one railroad car to another. Currently, many railroad car couplers use knuckle couplers that engage with each other to couple the railroad cars together. The operation of the knuckle requires that the knuckle be able to pivot around a knuckle pin. Traditional knuckle pins have been of a generally cylindrical shape and have been formed as solid pieces using various types of materials. Railroad car couplers are designed to meet various tolerances in order to control the distribution of force upon the couplers during buff and draft movement of the railroad cars.
As use takes its toll on couplers, couplers begin to fall out of tolerance and the distribution of force changes. In particular, knuckle pins may be subjected to bending forces due to out-of-tolerance couplers and traditional knuckle pins often fail when subjected to these bending force due to the stiffness of the knuckle pin. From the foregoing, it may be appreciated that a need has arisen for a knuckle coupler pin capable of surviving the bending forces found in railroad car coupling systems.
According to the present invention, a system and apparatus are provided to address the shortcomings of prior couplers. Among other things, the invention provides a coupler knuckle pin for use in a knuckle pin aperture of a railroad car coupler comprising a generally cylindrical body. The body has a longitudinal slot which extends between a first end of the body and a second end of the body. The coupler knuckle pin further comprises a first retaining element coupled to the first end of the body and operable to retain the body in the knuckle pin aperture.
According to another embodiment of the present invention, a railroad car coupling system comprises a coupler comprising a top portion and a bottom portion. The top portion has a first knuckle pin aperture disposed therethrough and the bottom portion has a second knuckle pin aperture disposed therethrough. The second knuckle pin aperture has a generally common longitudinal axis with the first knuckle pin aperture. The railroad car coupling system further comprises a knuckle pin comprising a generally cylindrical body. The body has a longitudinal slot extending between a first end and a second end of the body. The knuckle pin is disposable through the first and second knuckle pin apertures. The railroad car coupling system further comprises a knuckle rotatively coupled to the coupler by the knuckle pin. The knuckle has a third knuckle pin aperture disposed therethrough. The knuckle pin further extends through the third knuckle aperture. The railroad car coupling system further comprises a first retaining element coupled to the first end of the knuckle pin. The retaining element is engageable with the top portion to prevent downward movement of the knuckle pin through the first knuckle pin aperture.
According to yet another embodiment of the present invention, a railroad car comprises a coupler system coupled to the railroad car. The coupler system comprises a coupler, a knuckle pin and a knuckle. The coupler comprises a top portion and a bottom portion, the top portion having a first knuckle pin aperture disposed therethrough and the bottom portion having a second knuckle pin aperture disposed therethrough. The second knuckle pin aperture has a common longitudinal axis with the first knuckle pin aperture. The knuckle pin comprises a generally cylindrical body and a first retaining element. The body has a longitudinal slot extending between a first end and a second end of the body, and the knuckle pin is disposable through the first and second knuckle pin apertures. The first retaining element is coupled to the first end of the knuckle pin and is engageable with the top portion to prevent downward movement of the knuckle pin through the first knuckle pin aperture. The knuckle is rotatively coupled to the coupler by the knuckle pin and has a third knuckle pin aperture disposed therethrough. The first, second and third knuckle pin aperture have the common longitudinal axis and the knuckle pin extends through the third knuckle aperture.